Created new CLI entry point combining all mpdc-* commands.
For example 'mpdc playlist' instead of mpdc-playlist.
Added (dirty) argparse extension with abbreviation support.
I.e. 'mpdc playlist', 'mpdc play', 'mpdc pl' are all the same thing.
Also collectionmanager now gets updated using 'atexit' module.
Swithed to own Lastfm API key, so original maintainer's (nhrx) key is save from being banned.
Added lastfm track tags support and cli commands for getting lastfm info.
Renamed lastfm tags cache files.
Made Cache.read return empty dict instead of None when fails to read cache.
Stricter tags sanitization, update mpd's db before updating our's.
Some minor stuff
collection argument support for 'db check', matched files search fix.